Q: A particle of mass 2 g is initially displaced through 2 cm and then released. The frictional force constant due to air on it is 12×10-3 N/m. The restoring force constant is 50×10-3 N/m. If it is in oscillatory motion, its time period is
(a) π sec
(b) π / 2 sec
(c) 2π sec
(d) 4π sec
Ans: (b)